The attack came as protesters outside the compound rallied against a movie that unflatteringly portrays Islamās Prophet Mohammed. U.S. sources are giving conflicting accounts about whether theĀ attack was planned before the protest and whether the attackers used the protest as a diversion.

If youāre new to the story and need to catch up, here are six key things to know about the incident.

1) What happened?

On Tuesday night, protesters were outside the consulate in Benghazi, demonstrating against the video "Innocence of Muslims," which reportedly was made in California by a producer whose identity is unclear.

Eventually, a group of heavily armed militants "infiltrated the march to start chaos," according to Libyan Deputy Interior Minister WanisĀ al-Sharif.

Initial reports indicate the four-hour assault began around 10 p.m. as attackers pelted the U.S. Consulate complex's main compound with gunfire and rocket-propelled grenades . Within 15 minutes, the gunmen entered the building.

The attackers set the consulate ablaze - it's not clear how, though one senior U.S. official said a rocket-propelled grenade started the fire. American and Libyan security personnel tried to fight the attackers and the fire.

As the fire spread, three people - Stevens, Foreign Service information management officer Sean Smith and a U.S. regional security officer - were in a safe room, senior State Department officials said.

The three tried to leave when smoke filled the safe room. After the security officer escaped the building, he returned with others to try to rescue Stevens and Smith. Smith was found dead, apparently of smoke inhalation, officials said.

Stevens was missing. Libyans later said that bystanders found an unconscious Stevens and took him to a hospital, though U.S. officials could not confirm that account. His body was handed over to Americans at an airport; itās not clear how he died.

Two other Americans, whose names havenāt been released, were killed and two others were wounded during a gunbattle between security forces and militants at the complex, a senior administration official said.

2) Who did it, and why?

National Security Council spokesman Tommy Vietor said on Wednesday: āAt this stage it would be premature to ascribe any motive to this reprehensible act.ā

But sources tracking militant Islamist groups in eastern Libya say a pro-al Qaeda group responsible for a previous armed assault on the Benghazi consulate is the chief suspect.

They also note that the attack immediately followed a call from al Qaeda leader Ayman al-Zawahiri for revenge for the death in June of Abu Yahya al-Libi, a senior Libyan member of al Qaeda.

U.S. sources also have said they believed the attack was planned and used the protest as a diversion, though the sources could not say whether the attackers instigated the protest or merely took advantage of it.

A London think tank with strong ties to Libya was among those to speculate Wednesday that the attackers "came to avenge the death of Abu Yaya al-Libi."

It was "the work of roughly 20 militants, prepared for a military assault," the think tank Quilliam said, noting that there were no other protests against the film elsewhere in Libya.

āJihadists will want the world to believe that the attack is just a part of the protests against an amateur film produced in the U.S., which includes crude insults regarding the Prophet Mohammed. They will want the world to think that their actions represent a popular Libyan and wider Muslim reaction; thus, reversing the perception of jihadists being outcasts from their own societies,ā QuilliamĀ president Norman Benotman said.

The significance of the timing of the attack, which fell on the 11th anniversary of the September 11 attacks on New York and Washington, is unclear.

3) What is this movie that people were protesting?

Again, itās not clear whether the attack stemmed directly from outrage over the movie. But protesters outside the consulate did demonstrate against āInnocence of Muslimsā before the attack, as did demonstrators outside the U.S. Embassy in Cairo, 700 miles to the east of Benghazi.

An online trailer for the movie depicts Islam as a fraudulent religion bent on getting rid of nonbelievers. Cartoonish scenes show Mohammed as a womanizer, child molester and ruthless killer.

But the filmās actors and crew members released a statement Wednesday saying they were āgrossly misledā about the filmmakerās intent. An actress in the film who asked not to be identified said the original script did not include a Prophet Mohammed character, and that the actorsā lines had been changed post-production.

A casting call published in July 2011 in publications for actors identifies the working title of the movie as "Desert Warrior" and describes it as a "historical Arabian Desert adventure film."

The Wall Street Journal identified the filmmaker as Sam Bacile. The Journal reported that, in its telephone interview with Bacile, he characterized his film as "a political effort to call attention to the hypocrisies of Islam."

But CNN has not been able to contact him, and a search of public records on Sam BacileĀ came up empty. Casting further doubt on the filmmaker's identity, The Atlantic quoted a consultant of the filmmakerās as saying Sam BacileĀ is a pseudonym and saidĀ "he did not know Bacile's real name."

A senior defense official said the drones would be part of "a stepped-up, more focused search" for a particular insurgent cell that may have been behind the killings.

In June, a senior Libyan official told CNN that U.S. controllers were already flying the unmanned craft over suspected jihadist training camps in eastern Libya because of concerns about rising activity by al Qaeda and like-minded groups in the region.

Two U.S. Navy destroyers -Ā the USS LaboonĀ and the USS McFaul -are moving toward the coast of Libya, two U.S. officials told CNN. Both ships are equipped with tomahawk missiles that could be used if a strike was ordered.

About 50 U.S. Marines are headed to the Libyan capital, Tripoli, after the attack to beef up security in response to the attack, U.S. officials said Wednesday. The unit is specially trained to retake or guard diplomatic installations and other U.S. facilities in troubled regions.

Libya's leaders apologized for the attack. Prime Minister AbdurrahimĀ el-Keib called it a "cowardly, criminal act."

U.S. and NATO warplanes helped a Benghazi-based rebellion drive on Libyan strongman Moammar Gadhafi last year. Gadhafi was overthrown.

The militantsĀ suspected in Tuesday night's attack "are a very small minority" who are taking advantage of a fledgling democracy, Ali Suleiman Aujali, the Libyan ambassador the United States, told CNN's "Amanpour." "The good thing about this is the majority - 95, 98% of the Libyan people - care not for this," he said.

He was involved with Libya for several years, serving as the U.S. deputy chief of mission from 2007 to 2009. In 2011, Secretary of State Hillary Clinton sent him to Benghazi to be an envoy to the rebels during the revolt against Gadhafi.

Stevens graduated from the University of California, Berkeley, in 1982, then took a pause in his studies to join the Peace Corps, according to his State Department biography.

"Growing up in California, I didn't know much about the Arab world," he said in a State Department video prepared to introduce him to the Libyan people after his appointment as ambassador in May.

We will be better off when trolls stop blaming things like this on followers of the One who sacrificed Himself to bring peace to humanity. What we saw in Libya were people who were outraged and violent over their religious leader being "humiliated."

The basis of my faith is that our Leader allowed Himself to be humiliated by violent people in order to bring peace and redemption to people like me.

My intention was not to bing peace and redemption to people "like you" but to all people. Although no one can prove the existance of god; it also can not be proven that death is an end; but peoplenshould not waste their time worrying about something that is inevitable. Rather, all should spend more time understanding one another. Religious believe and non-believe is not the problem. The capacity for good and evil resides in all and people's choices and actions are at the foundation of all good and evil regardless of their religious believe. Countless people have died at the hands of pople's singular belief in their own religion and point of view is the only right way to live. I did not take a single human life while i was alive yet my supposed followers continue to do so. š¦

I am sorry your GOD is so small that a movie can humiliate him and your faith so week that violence is the only recorse to words. My GOD is big that he can not be humiliated by a film or anything else for that matter. How misguided and weak, I can't imagine basing my belief system around something so clearly misguided.

I'm muslim, and since our first days in school we were taught that any one who's not muslim is against us. And that they're going to hell. In the art class, I remember in my second grade, we were shown drawings of what appeared to be muslims being tortured and killed by 'infidels'. As a matter of fact, the Art text book for second grade in early 90's(Morocco) has a lot of picture and drawing like that ... / And every muslim has a strong belief that we are better, and that everyone else is bad and shall go to hell... I've never heard of something called ' tolerance ' or ' coexistence' in school. Jews are our most hated species. we actually pray for 'god' to destroy them and kill their children ... never hear an Imam say something like ' may god solve and end all the conflicts between us and our brothers the jew or christians" ... For me, I'm not saying that everyone else is perfect, but I believe that if our schools, jewish, and christian schools, if we have taught kids about coexistence and tolerance with one another, the would have had less terrorist attacks and killings from all parties in the name of religion ...Again , that song Imagine by john Lennon sums it up all. God Bless all humans

#7 Despite the fact the consulate had come under attack in June, no additional security was provided.
#8 The libyan troops that took the Marines off-shored duty of guarding the embassy seem to have been on the take and actually helped the attack.

Bruce, remember that "the fool has said in his heart 'there is no God'" so ignore Scott and his foolishness. He will find out soon enough that he was wrong and Christ is right. To try to reason with a fool is throwing pearls before swine. Swine trample.

God is real. To those who do not believe in a higher intelligence answer me this: Protein comes from DNA/RNA. DNA makes protein that is what DNA/RNA does. Nothing else makes protein only DNA/RNA. Now here is the rub....DNA is made completely of protein. Where did that protein come from? Not to mention how sophisticated DNA is, how unbelievable advanced blood cells are, heck look at Mitochondria! Look how macrophages eat up unwanted intruders in our blood streas. All of it was planned, all of it works in a magical synchronicity. If you can't see the magic around you that is intelligence then you are indeed blind and walking in darkness.

"Two U.S. Navy warships were moving toward the Libyan coast" - But nothing about warships moving to the Egyptian coast? Oh yeah, Egypt is a friend, don't want to fire rockets into Egypt to get those attackers. Libyan lives are worth less.

Who is Sam Bacile??? He should be arrested. There is free speech, but it doesn't mean it doesn't have consequences. In Islam you love God first and the Prophets second. You don't go make a movie like this. Hollywood needs to be held accountable if they really let someone like this produce a hate crime.

Making an offensive movie is not a crime in the United States, and I hope never will be - it has nothing to do with being in favor of offending people, but just that our own tradition of freedom of speech has to be protected no matter how much any religious group wants to demand that no one be allowed to speak against them.

For those of that don't subscribe to Islam (or religion at all, for that matter), we don't even believe in your god, much less "love" him. Your rules and laws based on such are null and meaningless to us.

A childish mind believing in ridiculous fairytale lies of a zombie who walked on water and tortured himself to death to please convince himself to forgive himself and others. Your belief is disgusting and states that keeping slaves is perfectly fine. You are a child afraid to think for yourself and asking priests to tell you what is right rather than grow a brain for yourself.

Tell that to the still born babies and infants who die of infant sudden death syndrome or the kid dying of flesh eating disease.
You have absolutely no evidence of the existence of god. You are a child afraid to think for yourself and face the finite time that your existence is doomed to. When this life ends your existence is over, no continues, that's all folks. Say what you will against it, but that just makes you a stupid coward to scared to face the evidence.

Your childish anger, over a childish view of what you apparantly don't understand, seems predicated upon "YOU CAN'T POSSIBLY HAVE EVIDENCE".

It would be ironic if you are the type of LIB who goes around telling people, "YOU CAN'T POSSIBLY KNOW HOW I FEEL". So I can only GUESS at what YOU KNOW? Then how can you be so DEFINITE about what I know?

To say, then, that YOU KNOW what it is that I DON'T know, is NOT a statement of fact, but rather an expression of YOUR FAITH. That is, you have a CONVICTED BELIEF about what I know, based on – not "facts", but your belief system and your personal deductions.

You're right, Scott, we don't. But we do have proof of the existence of evil: These spiteful diatribes of yours indicate your intolerance and hate for others who believe. Instead of "live and let live", you want others to believe as you do.

Where have I seen this before? Oh, yes...certain religions during their infancy....the KKK, Black Panthers, Adolf Hitler, Stalin, Mao...and of course....you.

Rudy Giuliani is such a fool with his comments on the statement issued at the beginning of the unrest by the US Cairo Embassy, before the attack in Benghazi happened. No wonder he has flunked out early in every Presidential Election contest that he has entered. CNN should only interview him about New York City matters, as he is clueless, it seems, about anything else.

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